3beta, 11alpha-hydroxylated pregnanes and process for preparing same



Unite 3,061,607 SBJIa-HYDROXYLATED PREGNANES AND PROC- ESS FOR PREPARING SAME Eugene P. Oliveto, Glen Ridge, and Hans Reimann, Bloomfield, N.J., assignors to Schering Corporation,

Bloomfield, N .J., a corporation of New Jersey N Drawing. Filed Mar. 9, 1961, Ser. No. 94,441 16 Claims. (Cl. 260-23955) CHI 3 0:

wherein R is CH F or Cl and R is H or OH, which may in turn be transformed as described below to the aforesaid 9,11-disubstituted pregnanes.

These compounds illustrated by (I) are readily transformed to the corresponding 9(11)-dehydro compounds via their 11-rnesylates or l1-tosylates as described in the chemical literature. The 9(11)-dehydrop-regnanes thus obtained are then converted touseful progestational compounds by addition to the 9(11)-double bond to give 9a,1lfi-dihaloprogesterones as described in Reimann et a1. patent applications S.N. 817,051, new Patent No. 3,009,- 930, and SN. 817,054, filed June 1, 1959, and to give 9a-halo-1lB-hydroxy and 9a-halo-1lfl-acyloxyprogesterones in the manner of Bergstrom et al., J.A.C.S., 81, 4432 (1959).

The novel intermediates of our invention which may be transformed by our novel process to the lla-hydroxypregnanes of Formula I as described below may be represented by the general formula:

OHsi

Pater 3,061,607 Patented Oct. 30, 1962 and b) with R being a member of the group consisting of H and OH; Y represents a configuration about the 5 and 6 carbon atoms selected from the group consisting of with X being a member of the group consisting of F, Cl and CH with the provision that when Y represents configuration (e), Z must represent configuration (b).

These intermediates may be prepared for example in the manner of the following general reaction sequence. In the reaction it is to be understood that although the group noted at the 3 and 11 positions of the S-pregnene: 3B,lloc-di0l and S-pregnene-ifi, la,17a-triol-20-one starting materials is hydroxyl it is within the scope of the invention that the said group also 'be an ester function such as acetyl, formyl, butyryl and the like.

In the general preparation gentrogenin is first converted to llwhydroxydiosgenin and thence to 5,16-pregnadiene- 3fi,1la-diol-20-one diacetate. The latter compound is converted to 5-pregnene-3B,1Ia-diol-ZO-one and to S-pregnene-3/3,1la,17a-triol-20-one (see, for example, Halpern et al., J.A.C.S., vol. 81, pages 439-441, January 20, 1959). These compounds serve as suitable starting materials for the preparative sequence of our invention.

Thus, in the manner of our invention 5-pregnene-3fl, 11u-diol-20-one is converted to the ZO-ketal by the use of ethylene/glycol in a solvent such as benzene in the presence of an acid catalyst such as p-toluenesulfonic acid, the 5,6-double bond is then epox-idized with a reagent such as perphthalic acid and the 5u,6u-epoxide is separated by a suitable procedure such as chromatography; The resulting 5a,6a-oxidoallopregnane-3fi,11a-diol-20one 20-ethylene ketal is treated with methylmagnesium iodide to give 6fi-methylallopregnane-313,50,lla-triol-ZO-one 20- ethylene ketal or with a hydrogen halide such as hydrogen fluoride or hydrogen chloride to give 6,8-fluoroand 65- chloroallopregnane 3/3,5ot,11a triol-20-one ZO-ethylene ketal. The ketal function is then removed by treatment with acid such as hot aqueous acetic acid to give the 6,8-substituted allopregnane-3/3,5 1,110t-tllOl-20-OI16S.' Reaction of the latter novel intermediate under controlled conditions with an oxidizing agent, for example with N- brornoacetamide at low temperatures, gives the corresponding 3-ketones. These may be dehydrated, and simultaneously or subsequently the C6 substituent may be epimerized to the 6a-configuration' by treatment with strong acid or base to give 6a-methy1, 6a-fluoroand 6a-chloro-4-pregnene-11a-ol-3,20-dione.

Similarly, 5-pregnene-3fi,11a,l7a-triol-20-one is converted to the 20-ethylenelcetal, epoxidized to give the 50t,6a-OXide which is then allowed to react with, for example, methylmagnesium iodide, hydrogen fluoride or hydrogen chloride to give respectively 6,6-methyl-, 6 3- fluoroand 6,8-chloroallopregnane-35,511,1la,l7a-tetra0l- 20-one 20-ethylene ketal. The ketal group is then hydrolyzed, the 3/3-hydroxy function oxidized and the resulting 3-ketosteroids dehydrated and the C6 substituent isomerized to give 6u-methyl-, 6u-fluoroand 6a-chloro-4- pregnene-l 1a,17a-diol-3,20-dione.

Alternatively, for the preparation of the 6-halopregnanes the 20-keto group does not have to be protected as the ketal. Thus 5-pregnene-3/3,llu-diol-20-one and 5-preg- I16I1e-3fl,11d,].70t-tl'iO1-20-Onii may be directly epoxidized with a reagent such as perphthalic acid and the corresponding 50,6oc-0Xid6 purified by chromatography. The oxido compounds thus obtained are treated with hydrogen fluoride or hydrogen chloride to give the corresponding 65 fiuoro-and fifi-chloroallopregnane-35,5ot,11u-triol-20- one and 6/3-fiuoroand 6,8-chloroallopregnane-3,8,5a,lla, 17u-tetraol-20-one, identical to the compounds obtained with ketal protection of the 20-ketone.

Although the following examples illustrate one method of preparing the novel intermediates and the process of the invention, it is to be understood that their purpose is purely by way of illustration and it is not intended in any way to limit the scope of the invention which may be determined only by reference to the appended claims.

EXAMPLE 1 5-Pregnene-35J1a,-Di0I-20-0ne ZO-Ethylene Ketal To a solution of 5.0 g. of 5-pregnene-3 5,1 la-diOl-ZO-OHG in 200 ml. of benzene and 10 ml. of ethylene glycol is added 0.2 g. of p-toluenesulfonic acid and the mixture heated under reflux in a flask provided with a Dean-Starke trap for six hours. The cooled reaction mixture is washed with 1% sodium bicarbonate solution and water. The dried benzene solution is concentrated to give the desired product.

EXAMPLE 2 5 a,6a-xid0all0pregnmz e-3 [3,1 1 u-DiOI-ZO-One Ethylene Ketal To a solution of 5.0 g. of the compound of Example 1 in 150 ml. of chloroform is added a solution of 3.8 g. of monoperphthalic acid in 42 ml. of ether and the mixture allowed to stand at 0 for 48 hours. The precipitate is then filtered off and the filtrate washed with aqueous sodium bicarbonate and water. The dried solution is concentrated to a residue consisting of the desried m,6 xepoxide in admixture with the 55,6,3-epoxide. The mixture is chromatographed on Florisil and the steroid eluted with mixtures of hexane, ether and acetone. Appropriate fractions are combined to give the desired pure 50:,6woxidopregnane.

EXAMPLE 3 6fl-Methylallopregnane-3p,5ot,Z1u-TI'IOZ-ZO-One ZO-Ezhylena Ketal A solution of 4.0 g. of the compound of Example 2 in 75 ml. of purified tetrahydrofuran is added slowly with stirring under nitrogen to a solution of methylmagnesium iodide prepared from 2.5 g. of magnesium and ml. of methyl iodide in ether. To the reaction mixture is added 200 ml. of benzene and ml. of tetrahydrofuran. The ether is distilled off and the mixture then allowed to heat under reflux for 18 hours. The reaction mixture is cooled in ice, diluted with ether and treated dropwise with a solution of 34 g. of ammonium chloride in 140 ml. of water. The organic layer is separated, washed with water, dried and concentrated. The residue is crystallized from acetone-ether to give the desired product.

4 EXAMPLE 4 (id-Methylallopregnanedflju,11u-Triol-20-One A solution of 5 g. of the compound of Example 3 in 200 ml. of aqueous acetic acid is heated at for two hours, then poured into ice-water. The precipitate is filtered and crystallized from acetone-hexane to give the desired product.

EXAMPLE 5 A solution of 1.0 g. of the compound of Example 4 in 10 ml. of acetone and one ml. of water is cooled to 0 and 0.5 g. of N-bromoacetamide is added. The mixture is kept at 3-5 for two hours, then the excess reagent is destroyed by the addition of a solution of 2 g. of sodium sulfite in 10 ml. of water. The mixture is poured into water and the resulting precipitate filtered and crystallized from acetone-hexane to give the desired material.

EXAMPLE 6 6a-Methyl-4-Pregnene-1 1 a-0l-3,20-Dione To a solution of 2 g. of the compound of Example 5 in 50 ml. of methanol is added 4 ml. of a 5% solution of potassium hydroxide in methanol and the mixture refluxed under nitrogen for one hour. The solution is slightly acidified with acetaic acid, diluted with water and concentrated under reduced pressure to give the crystalline compound of this example.

EXAMPLE 7 5 a,6a.-OxidoallopregnaneJp,1 1 m-Di0l-20-0ne Five grams of 5-pregnene-3/3,1la-diol-20-one is epoxidized with perphthalic acid and the product purified according to the procedure of Example 2. The product is crystallized from acetone-hexane.

EXAMPLE 8 To a solution of 500 mg. of the compound of Example 2 in 10 ml. of alcohol-free chloroform contained in a poly ethylene bottle and chilled to 15 is added a solution of about mg. of hydrogen fluoride in 5 ml. of chloroform and the mixture stirred at -l5 for 4 hours. The solution is washed with aqueous sodium bicarbonate and water, dried and concentrated. The residue is crystallized from methylene chloride-pentane to give the desired compound.

EXAMPLE 9 V 6fi-Fluoroallopregnane-3,6,5a,1 1 a-TriOl-ZO-OHQ EXAMPLE l0 6 fl-F luoroal l0pregnane-5 a,1 1a-Di0l-3,20-Di0ne A solution of 1.0 g. of the compound of Example 9 in acetone is treated with N-bromoacetamide according to the procedure of Example 5. The product is crystallized from acetone-hexane.

EXAMPLE 11 6 a-F luora-4-Pregn ene-Z 1 a-Ol-3,20-Di0ne A solution of 0.50 g. of the compound of Example 10 EXAMPLE 12 6 13-Chl0r0al lpregnane-3 5,5 oz, 1 1 a-Triol-ZO-One To a solution of 200 mg. of the compound of Example 7 in 10 ml. of chloroform, chilled to 0, is added a solution of 95 mg. of hydrogen chloride in 1 ml. of tetrahydrofuran. The mixture is allowed to stand at room temperature for tWo hours, then washed with dilute sodium bicarbonate solution and water. The dried organic solution is concentrated and the residue crystallized from acetone-hexane to give the desired compound.

EXAMPLE 13 6 ,B-Chloroallopregnane-S a,1 1 u-Diol-3,20-Di0ne A 100 mg. sample of the compound of Example 12 is oxidized with N-bromoacetamide according to the procedure of Example 5 to give the desired compound. The product may be crystallized from methylene chloridehexane.

EXAMPLE 14 6ot-Chlor0-4-Pregnene-11a-Ol-3,20-Di0ne Treatment of 50 mg. of the compound of Example 13 With hydrogen chloride according to the procedure of Example 11 gives the compound of this example.

EXAMPLE 15 5 -Pregnene-3 (3,] I a,17a-Tri0I-20-One ZO-Ethylene Ketal Substitute 5-pregnene-3/8,l la,l7 x-triol-20-one for 5- pregnene-3/3,llot-diol-20-one in the process of Example 1 to obtain the product of this example.

EXAMPLE l6 5 a,6ot-Oxid0all0pregnane-3 ,6,1 1 u,] 7 ot-TViOl-ZO-OIZQ ZO-Ethylene Keml Substitute the compound of Example 15 above in the process of Example 2 to obtain the product of this example.

EXAMPLE 17 6B-Methylallopregnane-3 3,5u,l10a,]7ct-Tetr0l-20-One ZO-Ethylene Ketal Substitute the compound of Example 16 above in the process of Example 3 to obtain the product of this example.

EXAMPLE 18 6 fi-M ethylallopregnanedflj a,] 1 a,17a-Tetrol--One Substitute the compound of Example 17 in the process of Example 4 to obtain the product of this example.

EXAMPLE 19 6 B-M ethylallopregnane-S 0a,] 1 (1,1 7a-Tri0l-3,20-Dione Substitute the compound of Example 18 in the process of Example 5 to obtain the product of this example.

EXAMPLE 20 6 a-M ethyl-4-Pregnene-1 1 0a,] 7a-Di0l-3,20-Di0ne Substitute the compound of Example 19 in the process of Example 6 to obtain the product of this example.

EXAMPLE 21 V 5 oc,6 a-Oxidoallopregnane-3 5,] 1 u,17a-Tri0l-20-0ne Substitute 5 -pregnene-3 ,B, l la,17a-triol-20-one in the 6 process of Example 2 to obtain the product of this example.

EXAMPLE 22 6 fi-F luoroallo pregnane-3 [3,5 0a,] 1 00,1 7a-Tezrol-20-One ZO-Ethylene Keta'l Substitute the compound of Example 16 in the process of Example 8 to obtain the product of this example.

EXAMPLE 23 6 fl-Fluoroallopregnane-3 5,5 0a,] 1 0a,] 7 a-T etrol-ZO-One Substitute the compound of Example 22 in the process of the first part of Example 9 to obtain the product of this example.

EXAMPLE 24 Substitute the compound of Example 23 in the process of Example 5 to obtain the product of this example.

EXAMPLE 25 6 OC-F lu0r0-4 -Pregnene-1 1 a,] 70t-DiO'l-3,20-Di0l'l Substitute the compound of Example 24 in the process of Example 11 to obtain the product of this example.

EXAMPLE 26 V 6B-Chl0r0allopregnane-3,l3,5a,1 1 0a,] 7 u-Tetrol-ZO-One Substitute the compound of Example 21 in the process of Example 12 to obtain the product of this example.

EXAMPLE 27 6 fl-Chloroallopregnane-S 0a,] 1 a,17a-Tri0l-3,20-Di0ne Substitute the compound of Example 26 in the process of Example 5 to obtain the product of this example.

EXAMPLE 28 6 u-Chl0ro-4-Pregnene-I 1 0a,] 7a-Dio [-3,20-Di0ne Substitute the compound of Example 27 in the process of Example 11 to obtain the product of this example.

We claim:

1. An intermediate for the preparation of therapeutically active 9,1l-disubstituted pregnanes selected from the group consisting of compounds of the general formula:

=0 --R HO- wherein R represents a member of the group consisting of H and OH; Y represents a configuration about the '5 and 6 carbon atoms selected from the group consisting of and OH 7 and X represents a member of the group consisting of F, Cl and CH 

1. AN INTERMEDIATE FOR THE PREPARATION OF THERAPEUTICALLY ACTIVE 9,11-DISUBSTITUTED PREGNANES SELECTED FROM THE GROUP CONSISTING OF COMPOUNDS OF THE GENERAL FORMULA: 